Impact of induced selection on fiber characteristics of Chiapas' wool-sheep breeds.

摘要

In the context of the genetic improvement programme of Chiapas' sheep breeds, the objective of this study was to evaluate the quantitative progress in some wool characteristics before and after empirical selection criteria were introduced by Tzotzil women. 116 wool samples of the 3 local sheep breeds collected in 1995 and 179 samples collected in 2003 were processed. Macroscopic studies showed significant changes in staple composition, with an increase in length in 2003 samples (11.4+or-2.2 vs. 8.3+or-1.7 cm; p<0.05), and a 19.6% increase in the proportion of long-coarse fibres (p<0.05), associated to an inversely proportional decrease (-4.9 p.100) in the amount of short-fine fibres. There was no change in yield after alcohol scouring. Comparisons among local breeds showed that the Chiapas White had longer staples (9.3+or-2.3 cm/6 months; p<0.05), and a lower amount of kemp fibres was observed in the Black Chamula sheep (0.7+or-1.2 p.100; p<0.05). This study demonstrated that inclusion of fleece quality selection criteria designed by Tzotzil women had a significant impact on those variables of major economic and cultural importance in the central mountain region of Chiapas, namely staple length and the proportion of long-coarse fibres..